The electron nuclear double resonance (ENDOR) spectra of cis-rich and trans-rich polyacetylenes have been recorded at temperatures in the range 4.21.9 K. The striking feature of these spectra is the similarity in both forms to the high-temperature ENDOR spectra of cis-rich polyacetylene reported previously. This observation demonstrates the existence of a common defect, a delocalized electron or soliton, in both materials. In the temperature range from 4.2 to 1.9 K, the hyperfine tensors are observed to be temperature independent for cis-rich polyacetylene. The hyperfine interactions for trans-rich polyacetylene are observed to be temperature dependent and can be characterized by a 1-K activation energy. At higher temperatures (6300 K), the trans-polyacetylene material is characterized by a 400-K activation energy for modulation of the hyperfine interactions. The consequences of these results for current soliton theories are discussed.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics